Cloning and characterization of the rat gene for the acid-labile subunit of the insulin-like growth factor binding protein complex.
The acid-labile subunit (ALS) of the ternary insulin-like growth factor-binding protein complex has a central role in controlling the bioavailability of circulating insulin-like growth factors. We have shown that gene expression of ALS is regulated by a number of factors, particularly growth hormone. Our aim was to characterize the ALS gene in order to define the mechanism of its regulation. Southern analysis suggests a single copy of the ALS gene in the rat genome. The protein-coding and 3'-untranslated regions span approximately 3.5 kilobases of rat genome and are divided into two exons. The 5' flanking region of the gene lacks a consensus TATA-box or Inr sequence, and primer extension and reverse transcriptase PCR experiments locate multiple transcriptional initiation sites between -505 and -385 nucleotides relative to the translational initiation codon. This putative promoter region, when inserted upstream of the luciferase reporter gene, directs luciferase expression when transfected into H4-II-E cells. Our data demonstrate the uncomplicated structure of the rat ALS gene, and the promoter function and presence of potential regulatory elements in the region upstream of the protein-coding sequence.
Delhanty
P J
PJ
Kolling Institute of Medical Research, University of Sydney, Royal North Shore Hospital, St Leonards, NSW, Australia.
Baxter
R C
RC
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA / Q000032:analysis / Q000235:genetics; D018076:DNA, Complementary / Q000032:analysis / Q000737:chemistry; D005796:Genes / Q000235:genetics*; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics*; D018969:Insulin-Like Growth Factor Binding Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology; D051381:Rats; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
D002352:Carrier Proteins; D018076:DNA, Complementary; D006023:Glycoproteins; D018969:Insulin-Like Growth Factor Binding Proteins; C075944:insulin-like growth factor binding protein, acid labile subunit; D004247:DNA